Reversible Ratiometric Probe Combined with the Time-Gated Method for Accurate In Vivo Gastrointestinal pH Sensing

2020 ◽  
Vol 12 (23) ◽  
pp. 25557-25564
Author(s):  
Shengming Cheng ◽  
Qingyun Liu ◽  
Xiaobo Zhou ◽  
Yuyang Gu ◽  
Wei Yuan ◽  
...  
Keyword(s):  
Ph Sensing ◽  
Gastrointestinal Ph ◽  
Ratiometric Probe

Design and in vivo evaluation of alginate-based pH-sensing electrospun wound dressing containing anthocyanins

2021 ◽  
Vol 28 (2) ◽  
Author(s):  
Ayben Pakolpakçıl ◽  
Bilgen Osman ◽  
Gökhan Göktalay ◽  
Elif Tümay Özer ◽  
Yasemin Şahan ◽  
...  
Keyword(s):  
Wound Dressing ◽  
Ph Sensing ◽  
In Vivo Evaluation

scholarly journals Anti-quenching NIR-II molecular fluorophores for in vivo high-contrast imaging and pH sensing

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Shangfeng Wang ◽  
Yong Fan ◽  
Dandan Li ◽  
Caixia Sun ◽  
Zuhai Lei ◽  
...  
Keyword(s):  
Ph Sensing ◽  
High Contrast ◽  
Contrast Imaging ◽  
High Contrast Imaging

scholarly journals Visual pH Sensors: From a Chemical Perspective to New Bioengineered Materials

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2952
Author(s):  
Luigi Di Costanzo ◽  
Barbara Panunzi
Keyword(s):  
Ph Monitoring ◽  
Three Dimensional ◽  
Lessons Learned ◽  
Background Information ◽  
Biological Macromolecules ◽  
Ph Sensing ◽  
Ph Sensors ◽  
Cellular Functions ◽  
Metal Organic

Many human activities and cellular functions depend upon precise pH values, and pH monitoring is considered a fundamental task. Colorimetric and fluorescence sensors for pH measurements are chemical and biochemical tools able to sense protons and produce a visible signal. These pH sensors are gaining widespread attention as non-destructive tools, visible to the human eye, that are capable of a real-time and in-situ response. Optical “visual” sensors are expanding researchers’ interests in many chemical contexts and are routinely used for biological, environmental, and medical applications. In this review we provide an overview of trending colorimetric, fluorescent, or dual-mode responsive visual pH sensors. These sensors include molecular synthetic organic sensors, metal organic frameworks (MOF), engineered sensing nanomaterials, and bioengineered sensors. We review different typological chemical entities of visual pH sensors, three-dimensional structures, and signaling mechanisms for pH sensing and applications; developed in the past five years. The progression of this review from simple organic molecules to biological macromolecules seeks to benefit beginners and scientists embarking on a project of pH sensing development, who needs background information and a quick update on advances in the field. Lessons learned from these tools will aid pH determination projects and provide new ways of thinking for cell bioimaging or other cutting-edge in vivo applications.

scholarly journals Ratiometric pH Sensing and Imaging in Living Cells with Dual-Emission Semiconductor Polymer Dots

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2923
Author(s):  
Piaopiao Chen ◽  
Iqra Ilyas ◽  
Su He ◽  
Yichen Xing ◽  
Zhigang Jin ◽  
...  
Keyword(s):  
Fluorescent Dyes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Fluorescein Isothiocyanate ◽  
Water Soluble ◽  
Ph Sensing ◽  
Dual Emission ◽  
Polymer Dots ◽  
Ratiometric Ph Sensing

Polymer dots (Pdots) represent newly developed semiconductor polymer nanoparticles and exhibit excellent characteristics as fluorescent probes. To improve the sensitivity and biocompatibility of Pdots ratiometric pH biosensors, we synthesized 3 types of water-soluble Pdots: Pdots-PF, Pdots-PP, and Pdots-PPF by different combinations of fluorescent dyes poly(9,9-dioctylfluorenyl-2,7-diyl) (PFO), poly[(9,9-dioctyl-fluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1′,3}-thiadazole)] (PFBT), and fluorescein isothiocyanate (FITC). We found that Pdots-PPF exhibits optimal performance on pH sensing. PFO and FITC in Pdots-PPF produce pH-insensitive (λ = 439 nm) and pH-sensitive (λ = 517 nm) fluorescence respectively upon a single excitation at 380 nm wavelength, which enables Pdots-PPF ratiometric pH sensing ability. Förster resonance energy transfer (FRET) together with the use of PFBT amplify the FITC signal, which enables Pdots-PPF robust sensitivity to pH. The emission intensity ratio (I517/I439) of Pdots-PPF changes linearly as a function of pH within the range of pH 3.0 to 8.0. Pdots-PPF also possesses desirable reversibility and stability in pH measurement. More importantly, Pdots-PPF was successfully used for cell imaging in Hela cells, exhibiting effective cellular uptake and low cytotoxicity. Our study suggests the promising potential of Pdots-PPF as an in vivo biomarker.

Dual-emission carbon dots as biocompatible nanocarrier for in vitro/in vivo cell microenvironment ratiometric pH sensing in broad range

2019 ◽  
Vol 16 (10) ◽  
pp. 2081-2092 ◽  
Author(s):  
Somayeh Hamd-Ghadareh ◽  
Abdollah Salimi ◽  
Fardin Fathi ◽  
Farzad Soleimani
Keyword(s):  
Carbon Dots ◽  
Ph Sensing ◽  
Dual Emission ◽  
Cell Microenvironment ◽  
Ratiometric Ph Sensing

scholarly journals Vascular Abnormalities in Mice Deficient for the G Protein-Coupled Receptor GPR4 That Functions as a pH Sensor

2006 ◽  
Vol 27 (4) ◽  
pp. 1334-1347 ◽  
Author(s):  
Li V. Yang ◽  
Caius G. Radu ◽  
Meenakshi Roy ◽  
Sunyoung Lee ◽  
Jami McLaughlin ◽  
...  
Keyword(s):  
G Protein ◽  
Mesangial Cells ◽  
Ex Vivo ◽  
Extracellular Ph ◽  
Ph Sensing ◽  
G Protein Coupled Receptor ◽  
Vascular Abnormalities ◽  
G Protein Coupled

ABSTRACT GPR4 is a G protein-coupled receptor expressed in the vasculature, lung, kidney, and other tissues. In vitro ectopic overexpression studies implicated GPR4 in sensing extracellular pH changes leading to cyclic AMP (cAMP) production. To investigate its biological roles in vivo, we generated GPR4-deficient mice by homologous recombination. Whereas GPR4-null adult mice appeared phenotypically normal, neonates showed a higher frequency of perinatal mortality. The average litter size from GPR4−/− intercrosses was ∼30% smaller than that from GPR4+/+ intercrosses on N3 and N5 C57BL/6 genetic backgrounds. A fraction of knockout embryos and neonates had spontaneous hemorrhages, dilated and tortuous subcutaneous blood vessels, and defective vascular smooth muscle cell coverage. Mesangial cells in kidney glomeruli were also significantly reduced in GPR4-null neonates. Some neonates exhibited respiratory distress with airway lining cell metaplasia. To examine whether GPR4 is functionally involved in vascular pH sensing, an ex vivo aortic ring assay was used under defined pH conditions. Compared to wild-type aortas, microvessel outgrowth from GPR4-null aortas was less inhibited by acidic extracellular pH. Treatment with an analog of cAMP, a downstream effector of GPR4, abolished microvessel outgrowth bypassing the GPR4-knockout phenotype. These results suggest that GPR4 deficiency leads to partially penetrant vascular abnormalities during development and that this receptor functions in blood vessel pH sensing.

scholarly journals Fluorescence lifetime imaging of upper gastrointestinal pH in vivo with a lanthanide based near-infrared τ probe

2019 ◽  
Vol 10 (15) ◽  
pp. 4227-4235 ◽  
Author(s):  
Yingying Ning ◽  
Shengming Cheng ◽  
Jing-Xiang Wang ◽  
Yi-Wei Liu ◽  
Wei Feng ◽  
...  
Keyword(s):  
Fluorescence Lifetime ◽  
Near Infrared ◽  
Lanthanide Complex ◽  
Fluorescence Lifetime Imaging ◽  
Ph Responsive ◽  
Gastrointestinal Ph ◽  
Lifetime Imaging ◽  
Upper Gastrointestinal

Lanthanide complex was successfully applied in the design of pH-responsive NIR τ probe for quantitative in vivo imaging.

Precision delivery of RAS-inhibiting siRNA to pancreatic cancer via peptide-based nanoparticles.

2017 ◽  
Vol 35 (4_suppl) ◽  
pp. 287-287 ◽  
Author(s):  
Matthew S. Strand ◽  
Hua Pan ◽  
Bradley Krasnick ◽  
Xiuli Zhang ◽  
Peter S. Goedegebuure ◽  
...  
Keyword(s):  
Cell Death ◽  
Fluorescence Microscopy ◽  
Cell Viability ◽  
Imaging System ◽  
Sirna Delivery ◽  
Ph Sensing ◽  
Stromal Component ◽  
Cancer Types

287 Background: Greater than 95% of pancreatic adenocarcinomas (PDACs) are driven by KRAS activation; yet, despite decades of work, no RAS inhibitors have reached the clinic. Furthermore, the delivery of therapeutic agents of any kind to PDAC has been hindered by the extensive desmoplasia that accompanies these tumors. Herein, we show that serum-stable and pH-sensing nanoparticles (NPs) are taken up by PDAC cells, can deliver KRAS-specific siRNA into the cytoplasm and inhibit KRAS expression, thereby causing cell death. We go on to use a spontaneous model of pancreas cancer to show that this system can effectively deliver siRNA to stroma-rich tumors. Methods: The murine PDAC cell line KP1 was tested for NP uptake in vitro utilizing fluorescent siRNA NPs (fNPs) in combination with confocal microscopy and flow cytometry. KP1 cells were treated with KRAS-siRNA NP, and KRAS expression and cell viability were assessed with RT-PCR and CellTiter-Glo, respectively. Mice bearing subcutaneous KP1 tumors and KPPC mice with spontaneous PDAC were injected with fNP, and tumor fluorescence was assessed using an in vivo imaging system and fluorescence microscopy. Results: KP1 cells take up fNP in vitro, with > 99% of cells positive for fluorescent signal at 24 hours. Treatment with KRAS-siRNA NP of KP1 cells reduced KRAS expression by 69% (see Figure) and reduced cell viability by 45% compared to untreated and scramble-siRNA treated controls. Gemcitabine demonstrated an additive effect with anti-KRAS therapy. Tumors from KP1 cells grown in mice, and tumors from KPPC mice, were strongly fluorescent 24 hours after IV injection of fNP. Fluorescence microscopy showed successful delivery of fNP to tumors. Conclusions: Our NP system can precisely deliver siRNA to KP1 cells and spontaneous PDAC, overcoming the predominant stromal component in these tumors. KRAS-siRNA delivery downregulates KRAS expression, leading to cell death. This represents a novel treatment for PDAC. Furthermore, with its ability to deliver siRNA into the tumor microenvironment and suppress a known oncogene, this platform could be used to target other putative drivers of tumor progression across various cancer types.

Low temperature synthesis of phosphorous and nitrogen co-doped yellow fluorescent carbon dots for sensing and bioimaging

2015 ◽  
Vol 3 (33) ◽  
pp. 6813-6819 ◽  
Author(s):  
Xiaojuan Gong ◽  
Wenjing Lu ◽  
Yang Liu ◽  
Zengbo Li ◽  
Shaomin Shuang ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Ph Sensing ◽  
Low Temperature Synthesis ◽  
Low Toxicity ◽  
Doped Carbon Dots ◽  
Fluorescent Carbon Dots ◽  
Co Doped ◽  
High Output

A simple and high-output strategy for the fabrication of yellow fluorescent phosphorous and nitrogen co-doped carbon dots (P,N-CDs) is developed. P,N-CDs possess distinctive photoluminescence properties, low toxicity, and biocompatible. P,N-CDs are potentially useful for versatile applications such as pH sensing, in vitro and in vivo imaging.

scholarly journals Time-resolved fluorescence analysis of LHCII in the presence of PsbS at neutral and low pH

2018 ◽  
Author(s):  
Emanuela Crisafi ◽  
Maithili Krishnan ◽  
Anjali Pandit
Keyword(s):  
Lipid Membranes ◽  
Light Stress ◽  
Fluorescence Analysis ◽  
Low Ph ◽  
Photochemical Quenching ◽  
Ph Sensing ◽  
Fluorescence Lifetimes ◽  
Light Harvesting Complexes ◽  
Time Resolved

In plant chloroplast membranes, non-photochemical quenching (NPQ) is activated as a response to a low luminal pH and controlled by the pH-sensing protein PsbS. It has been proposed that PsbS directly interacts with the light-harvesting complexes (LHCII) of Photosystem II, inducing quenching of LHCII Chl excitations, whilst others proposed that PsbS has an indirect role in controlling the organization of the membrane. In this study, we systematically test the influence of low pH and PsbS on the fluorescence lifetimes of membrane-embedded spinach LHCII. The proteoliposome preparations contain LHCII in mild quenched states, aimed to mimic fluorescence conditions of dark-adapted leaves. We find that under those conditions, acidification and the presence of PsbS do not have significant effect on the LHCII Chl fluorescence lifetimes. This supports a view in which the functional role of PsbS consists of re-organizing the thylakoid membrane under light stress, rather than creating direct quencher states. The dimeric form of PsbS appears to be destabilized in lipid membranes compared to detergent micelles, which might explain why the low-pH PsbS crystal structure is dimeric, while in vivo activation of PsbS has been correlated with its monomerization at low pH.

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